1. Field of the Invention
The present invention relates to a vehicle seat of retractable type which allows a seat back to be folded onto a seat cushion and further allows both seat back and seat cushion to be rotated donwardly from an upper use position to a lower storage position close to a point where a seat occupant's feet rest on, so that a whole of the seat can be retracted and stored in the storage position.
2. Description of Prior Art
Most of conventional retractable vehicle seats, as disclosed in the Japanese Laid-Open Patent Publication No. 2000-108745 for instance, are operable manually to fold and move both seat back and seat cushion to a storage position. According to such prior art, a seat cushion is rotatably provided on an upper area of a floor where the seat itself is set in a normal use position, i.e. a use position, and also movably supported by a link mechanism disposed forwardly of the seat, which extends from the seat cushion to a lower area of the floor which corresponds to a place on which seat occupant's feet rest. This lower area of floor is the storage position where the seat is retracted and stored. When it is desired to move the seat to the storage position, the seat back is first folded onto the seat cushion, and then, a seat occupant has to manually rotate the thus-folded seat forwardly and donwardly to the storage position. Of course, the seat occupant can manually return the stored seat to the use position for normal use.
However, this kind of manually retractable vehicle seat encounters a great and troublesome labor on the user's side because of a relatively heavy weight of the seat and a too narrow space surrounding the seat in which the user has to move the seat to either of the use and storage positions. Further, the seat requires the following technically difficult points: (i) the seat cushion must be set in a substantially horizontal state in both of the use and storage positions, and, in the storage position, the seat back folded to the seat cushion must also be in a substantially horizontal state since it is used as one of floor, (ii) during the manual operation for moving the seat to either of the use and storage positions, the seat is inevitably inclined forwardly, and therefore, it is structurally required to prevent interference and contact of the forwardly inclined seat with the upper area of floor, and (iii) in such manual operation for moving the seat to either of the use and storage positions, it is necessary to unlock and lock the seat from the upper area of floor. Apparently, a lot of troublesome operations are required in this particular manual retractable seat, thereby resulting in a great degradation of usability and workability of the seat.
One can of course contemplate on an electrically operated or powered structure of retractable seat to solve the foregoing problems. But, if such powered arrangement is applied to the above-stated prior-art seat, the link mechanism disposed forwardly of the seat will be a technical obstacle against operation of a motor in order to realize smooth movement of the seat to either of the use and storage positions in a manner analogous to manual operation by person. To overcome this difficulty will involve a complicated structure and mechanism and increase costs accordingly. Hence, it has been desired to attain a simplified and low-cost structure of powered retractable seat.